Arctic transport and marine operation system

Abstract

A buoyant, cylindrical metal drum, having a plurality of elongate teeth protruding outwardly from the periphery thereof is mounted for rotation about its longitudinal axis in a generally U-shaped framework. The frame is pivotally attached to the front of a tug vessel and the drum may be steered, with respect to the boat, by moving the mounting frame about the pivot point. An internal power source and an eccentric counterweight, which may include a fuel storage container for the power source, are stationarily mounted within the drum which is rotated about the counterweight as an inertial reference. When the drum is rotated by its internal power source and moved against the water/ice interface of a floating arctic ice sheet, the moving teeth on the drum cut the ice and clear a path for movement of the drum and the tug boat through the ice covered water. In an embodiment of the invention wherein substantial heat is generated by the drum power source, for example where a gas turbine engine is employed, the heat is preferably directed into the region surrounding the drum and in front of the tug to prevent the cut ice from immediately refreezing upon contact with the sub-zero air temperatures. The tug mounted rotating cutter can be used to tow a drilling rig in arctic waters, and subsequently operated to cut an annular channel around the resulting 'ice island' to isolate the rig from the movement of the surrounding ice sheet.